The Door of the Sheep (John 10:7)
Sheep are totally dependent on the shepherd. Their problem is that they often forget and go their own way. To return to the safety of the shepherd, all they must do is listen for his voice.
At night, when sheep are most vulnerable to being attacked, a shepherd will keep them safely in a pen. There is but one way in, and that is through the door. Jesus, the door of the sheep, will protect us.